Detection device

Abstract

To provide a detection device capable of suppressing a change in the shape of a sensor substrate as much as possible even when the shape of a hub bearing is changed.SOLUTION: The detection device includes a sensor substrate 100 and a target member 80. The sensor substrate 100 is provided at a position shifted to the knuckle 15 side in the axial direction with respect to the flange portion 62 of the hub bearing 40. The detection device includes a bracket member 120. The bracket member 120 has a bracket base portion extending in the circumferential direction and a thick portion extending from the bracket base portion toward the flange portion 62 in the axial direction. The sensor substrate 100 is fixed to the bracket member 120 in a state where the first plate surface of the sensor substrate 100 faces the target member 80 and the second plate surface of the sensor substrate 100 is in contact with the thick portion. In the thick portion, a plurality of ventilation holes, which are holes penetrating in the radial direction, are formed side by side in the circumferential direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a detection device. [Background technology]

[0002] Conventionally, an inductive rotation angle sensor has been known that includes a rotor provided on a rotating shaft of a mechanical device and a sensor body disposed opposite the rotor in the axial direction of the rotating shaft. Such a sensor is described, for example, in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5447345 Summary of the Invention [Problem to be solved by the invention]

[0004] A detection device is known that is applied to a wheel unit that includes a vehicle knuckle and a hub bearing that rotatably supports the vehicle wheel relative to the knuckle. The hub bearing includes a first bearing member (e.g., an outer ring member), a second bearing member (e.g., an inner ring member), and rolling elements. The first bearing member has a first cylindrical portion that extends in the axial direction, which is the direction of the rotational center axis of the hub bearing, and is fixed to the knuckle. The second bearing member has a second cylindrical portion that is provided at a position facing the first cylindrical portion in a radial direction perpendicular to the axial direction, and a flange portion that extends radially outward from the second cylindrical portion. The rolling elements are provided between the first cylindrical portion and the second cylindrical portion.

[0005] The detection device includes a sensor board and a detection target portion as components for detecting a force acting on a wheel. The sensor board is provided on the flange portion on the knuckle side in the axial direction. The detection target portion is provided on a portion of the flange portion facing the sensor board in the axial direction and has an annular shape extending circumferentially of the second cylindrical portion. The detection target portion has convex portions that protrude toward the knuckle body in the axial direction and portions that recede from the convex portions on the opposite side of the knuckle body in the axial direction, arranged alternately in the circumferential direction. The sensor board outputs a voltage signal corresponding to the relative displacement of the detection target portion with respect to the sensor board. Force is detected based on the output voltage signal.

[0006] For example, if the type of vehicle on which the detection device is to be installed changes, the shape of the hub bearing may change. In this case, the fixing method of the sensor board must be selected according to the shape, and there is a concern that the shape of the sensor board may need to be changed depending on the shape.

[0007] A primary object of the present disclosure is to provide a detection device that can minimize changes in the shape of a sensor substrate even when the shape of a hub bearing changes. [Means for solving the problem]

[0008] The present disclosure provides a vehicle wheel; a hub bearing that rotatably supports the wheel relative to a knuckle of the vehicle; a disc rotor constituting a brake device; A detection device applied to a wheel unit comprising: The hub bearing is a first bearing member having a first cylindrical portion extending in an axial direction that is the direction of the rotational center axis of the hub bearing and fixed to the knuckle; a second bearing member including a second cylindrical portion provided at a position facing the first cylindrical portion in a radial direction perpendicular to the axial direction, and a flange portion extending radially outward from the second cylindrical portion and to which the disk rotor is fixed; a rolling element provided between the first cylindrical portion and the second cylindrical portion; the second bearing member is rotatably supported relative to the knuckle, the disk rotor has an annular disk sliding portion that is disposed radially outward relative to the hub bearing, a detection target portion that is provided on the knuckle side of the flange portion in the axial direction and has an annular shape extending in a circumferential direction of the second cylindrical portion; a sensor substrate; Equipped with The detection target portion is provided with convex portions that protrude toward the knuckle in the axial direction and portions that recede toward the opposite side of the knuckle from the convex portions in the axial direction, alternately in the circumferential direction, The sensor substrate outputs a voltage signal corresponding to the relative displacement of the detection target with respect to the sensor substrate.

[0009] The present disclosure includes a bracket member disposed between the knuckle and the detection target portion in the axial direction, The bracket member is a bracket base portion that is disposed radially outward relative to an outer cylindrical portion that is a cylindrical portion located radially outward of the first cylindrical portion and the second cylindrical portion and that extends along the circumferential direction; a thick portion extending from the bracket base portion toward the flange portion in the axial direction; and the sensor board is fixed to the bracket member with a plate surface of the sensor board facing the detection target and the sensor board abutting against the thick portion, The thick portion has a plurality of ventilation holes, which are holes that penetrate in the radial direction, formed side by side in the circumferential direction.

[0010] The bracket member determines the relative position of the sensor board and the detection target. This minimizes the effect of changes in the shape of the hub bearing on the mounting of the sensor board, which is required to position the first plate surface of the sensor board facing the detection target. As a result, even if the shape of the hub bearing changes depending on the type of vehicle, changes in the shape of the sensor board can be minimized.

[0011] A circular disk sliding part is disposed radially outward of the hub bearing. A blade pad is pressed against the disk sliding part to apply braking force to the wheel. In this case, the disk sliding part generates heat, causing the temperature of the sensor substrate, which is disposed radially inside the disk sliding part, to rise. If the temperature of the sensor substrate rises, there is a concern that the reliability of the sensor substrate may be reduced, for example, affecting the output voltage signal of the sensor substrate.

[0012] Therefore, in the present disclosure, the sensor board is fixed to the bracket member with the second plate surface abutting against the thick portion, and the thick portion has a plurality of ventilation holes that penetrate in the radial direction and are aligned in the circumferential direction, thereby suppressing a temperature rise in the thick portion and, in turn, suppressing a temperature rise in the sensor board. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a perspective view of a wheel unit according to the first embodiment. [Figure 2] FIG. [Figure 3] Enlarged view of a portion of Figure 2. [Figure 4] FIG. [Figure 5] FIG. 3 is a perspective view of the wheel unit seen from the flange side. [Figure 6] FIG. 10 is a view of the target member as seen from the knuckle side. [Figure 7] FIG. 2 is a diagram showing the electrical configuration of a sensor substrate and a processing unit. [Figure 8] FIG. 4 is a perspective view of the bracket member as seen from the knuckle side. [Figure 9] FIG. 4 is a perspective view of the bracket member as viewed from the flange portion side. [Figure 10] FIG. 10 is a perspective view of the bracket member with the sensor board fixed thereto. [Figure 11] FIG. [Figure 12] FIG. 10 is a perspective view of a bracket member according to a second embodiment, as viewed from the knuckle side. [Figure 13] FIG. 4 is a perspective view of the bracket member as viewed from the flange portion side. [Figure 14] FIG. 10 is a perspective view of the bracket member with the sensor board fixed thereto. DETAILED DESCRIPTION OF THE INVENTION

[0014] Several embodiments will be described with reference to the drawings. In several embodiments, functionally and / or structurally corresponding and / or associated parts may be assigned the same reference numerals or reference numerals that differ in the hundredth or more digit. For corresponding and / or associated parts, reference may be made to the descriptions of other embodiments.

[0015] First Embodiment A first embodiment of a detection device according to the present disclosure will be described below with reference to the drawings. The detection device of this embodiment is configured to be able to calculate the force acting on wheels (drive wheels or driven wheels) as rotating bodies. A vehicle equipped with wheels is, for example, a four-wheeled passenger vehicle (for example, private or commercial use) having two front wheels and two rear wheels. However, the vehicle is not limited to this, and may be a vehicle other than a four-wheeled vehicle, such as a two-wheeled vehicle. Furthermore, the use of the vehicle is not limited to passenger use.

[0016] The wheel unit 10 as a mechanical device will be described using Figures 1 to 11. To explain some of the figures, Figure 1 is a perspective cross-sectional view in which the wheel unit 10 is partially cut away, and Figure 2 is a cross-sectional view in which the wheel unit 10 is cut along a plane that passes through the center of rotation of the wheel unit 10 and extends vertically. Figure 3 is a partially enlarged view of Figure 2. Figure 4 is an exploded perspective view of the wheel unit 10. Figure 5 is a perspective view of the wheel unit 10 as viewed from the flange portion 62 side.

[0017] As shown in Figures 1 and 2, the wheel unit 10 includes a wheel 11 and a tire 14 that constitute a wheel. The wheel 11 includes a cylindrical rim portion 12 and a disc portion 13 provided at the outer end of the rim portion 12 in the vehicle width direction. The disc portion 13 includes a disc mounting portion 18 located in the center of the disc portion 13, and spoke portions 19 that extend radially from the disc mounting portion 18 to the rim portion 12. The tire 14 is mounted on the outer periphery of the rim portion 12.

[0018] As shown in Figures 1 to 5, the wheel unit 10 includes a brake device 20 and a hub bearing 40. The brake device 20 is a disc-type friction braking device and includes a disc rotor 21 that is disk-shaped overall, and a brake caliper 33. The brake caliper 33 is operated by hydraulic pressure, an electric signal, or the like, and includes a pair of brake pads that come into contact with the disc rotor 21 to generate braking force, a piston that presses the brake pads against the disc rotor 21, and a caliper body that supports the brake pads and the piston. As shown in Figure 4, the brake caliper 33 is fixed to the knuckle 15, which is its base, by a bolt 34.

[0019] In the following, the direction in which the rotational center axis of the hub bearing 40 (specifically, for example, the inner ring member 60 of the hub bearing 40) extends is referred to as the axial direction, the direction extending radially from the rotational center axis is referred to as the radial direction, and the direction extending circumferentially around the rotational center axis is referred to as the circumferential direction.

[0020] The disc rotor 21 of this embodiment is a ventilated disc having an internal cavity for ventilation. As shown in FIGS. 2 and 3 , the disc rotor 21 has a hat portion 22 and a disc sliding portion 23. The hat portion 22 is attached to the hub bearing 40. The hat portion 22 has a disk-shaped bottom surface portion 24 and a disc peripheral wall portion 25. A mounting hole 26 is formed in the center of the bottom surface portion 24. Bolt insertion holes 27 that axially penetrate the bottom surface portion 24 are formed in a circumferential direction around the mounting hole 26. The disc rotor 21 is connected to the hub bearing 40 using the mounting holes 26 and the bolt insertion holes 27. The disc peripheral wall portion 25 is cylindrical and extends from the outer circumferential edge of the bottom surface portion 24, forming the peripheral surface of the hat portion 22.

[0021] A disc sliding portion 23 is connected to the end of the disc peripheral wall portion 25 opposite the bottom surface portion 24. The disc sliding portion 23 is formed to protrude outward in an annular shape from the disc peripheral wall portion 25. The front and back surfaces of the disc sliding portion 23 form a pair of sliding surfaces that are pressed against by the brake pads.

[0022] The disc sliding portion 23 includes an inner disc portion 28, an outer disc portion 29 disposed on the outer side of the inner disc portion 28, and fins 30. The fins 30 connect the inner disc portion 28 and the outer disc portion 29 at multiple locations in the circumferential direction. The fins 30 extend radially, and the space surrounded by the inner disc portion 28, the outer disc portion 29, and the fins 30 forms air passages 30a penetrating in the radial direction (diameter direction). The air passages 30a are passages extending from an air intake port 31 formed on the radially inner side of the disc sliding portion 23 to an air exhaust port 32 formed on the radially outer side. The air passages 30a extend linearly in the radial direction, and multiple air passages 30a are formed side by side in the circumferential direction. Note that the air passages 30a are not limited to those extending linearly, and may extend in an arc, for example.

[0023] The hub bearing 40 is a rolling bearing (specifically, a radial ball bearing) and includes an outer ring member 50 (corresponding to the "first bearing member"), an inner ring member 60 (corresponding to the "second bearing member"), and a plurality of rolling elements 41 (specifically, balls) arranged between the outer ring member 50 and the inner ring member 60. The hub bearing 40 of this embodiment has a structure in which the rolling elements 41 are arranged in two rows in the axial direction. Note that the hub bearing 40 may also be a radial roller bearing provided with rollers as the rolling elements 41.

[0024] The inner ring member 60 includes an inner cylindrical portion 61 (corresponding to a "second cylindrical portion") extending in the axial direction, and a flange portion 62 extending radially from a first end of the inner cylindrical portion 61 in the axial direction. A shaft insertion hole 63 is formed in the inner cylindrical portion 61, penetrating it in the axial direction. A spline is formed on the inner peripheral surface of the shaft insertion hole 63. A shaft (not shown) to which rotational power of a traveling power source such as a motor is transmitted is fitted in the shaft insertion hole 63.

[0025] The outer ring member 50 has an outer cylindrical portion 51 (corresponding to a "first cylindrical portion") provided at a position facing radially outward from the inner cylindrical portion 61. A rolling element 41 is provided between the outer cylindrical portion 51 and the inner cylindrical portion 61.

[0026] The flange portion 62 is disk-shaped and extends radially outward beyond the outer cylindrical portion 51. A plurality of bolt insertion holes 64, through which hub bolts 17 for fixing the wheel 11 are inserted, are formed in the flange portion 62 and aligned in the circumferential direction. In this embodiment, five hub bolts 17 are formed and aligned in the circumferential direction. Therefore, five bolt insertion holes 64 are also formed.

[0027] The wheel unit 10 is provided with a dust cover 70, which is a heat shield. The dust cover 70 is provided on the inner side in the vehicle width direction of the hub bearing 40 and the disc sliding portion 23 of the disc rotor 21. The dust cover 70 extends radially outward beyond the outer peripheral edge of the disc sliding portion 23.

[0028] The wheel unit 10 is equipped with a detection device. The detection device is provided in the inner space of the wheel 11 and includes a target member 80 and a sensor substrate 100. The detection device is a device for detecting the rotational speed of the wheel consisting of the wheel 11 and tire 14, the lateral force Fy acting between the ground contact surface (ground) GL and the wheel (specifically, the tire 14), and the force acting between the ground contact surface GL and the wheel in a direction perpendicular to the ground contact surface GL (hereinafter referred to as vertical load Fz). The direction in which the lateral force acts and the direction in which the vertical load acts are orthogonal. For example, the calculated rotational speed, lateral force, and vertical load are used in a control device (specifically, an ECU: Electronic Control Unit) provided in the vehicle to control the running of the vehicle, which is a moving object. The structure of the detection device will be described below.

[0029] The target member 80 is made of a metal material through which magnetic flux flows. Specifically, for example, the target member 80 is made of a paramagnetic metal material (e.g., aluminum) having a relative permeability greater than 1, or a ferromagnetic metal material (e.g., iron) having a relative permeability greater than 1. The target member 80 has an annular shape extending in the circumferential direction about the central axis of rotation of the hub bearing 40. The target member 80 is provided at a position facing the sensor substrate 100 in the axial direction without contacting the sensor substrate 100. The target member 80 is fixed to, for example, the flange portion 62, and rotates integrally with the inner ring member 60.

[0030] As shown in Figures 4 and 6, protrusions 82, each having a flat surface 82a and projecting toward the knuckle 15 in the axial direction (i.e., toward the inside in the vehicle width direction), are formed side by side in the circumferential direction on the portion of the target member 80 facing the sensor board 100. The flat surfaces between the protrusions 82 lined up in the circumferential direction are recesses 83. As a result, the protrusions 82 and recesses 83 are alternately provided in the circumferential direction. In this embodiment, 12 pairs of protrusions 82 and recesses 83 are provided. The protrusions 82 and recesses 83 form a detection target portion 84.

[0031] 6, LCi indicates the center axis of the inner ring member 60. In this embodiment, the angle α1 formed by the axis passing through the center axis LCi and one circumferential end of the protruding portion 82 and the axis passing through the center axis LCi and the other circumferential end of the protruding portion 82 is equal to the angle α2 formed by the axis passing through the center axis LCi and one circumferential end of the recessed portion 83 and the axis passing through the center axis LCi and the other circumferential end of the recessed portion 83. Therefore, the circumferential length of the multiple protruding portions 82 and the circumferential length of the multiple recessed portions 83 are equal to each other.

[0032] Next, a configuration for fixing the wheel 11, the disc rotor 21, and the target member 80 to the flange portion 62 will be described.

[0033] As shown in Fig. 3, the disc mounting portion 18 has a bolt insertion hole 18a formed therethrough in the axial direction. With the bottom surface portion 24 and the disc mounting portion 18 overlapping the mounting surface 62b of the flange portion 62, a hub bolt 17 is inserted into the bolt insertion holes 27, 18a. A nut 35 is threaded onto the hub bolt 17, thereby fixing the disc mounting portion 18 and the disc rotor 21 to the hub bearing 40. This makes the target member 80, disc rotor 21, and inner ring member 60 coaxial, and causes the target member 80, disc rotor 21, and wheel 11 to rotate integrally.

[0034] Next, the sensor substrate 100 will be described.

[0035] The sensor board 100 is a so-called eddy current inductive sensor. The sensor board 100 has a flat shape with its thickness direction aligned with the axial direction. The sensor board 100 is provided in an arrangement space that is adjacent to the flange portion 62 on the inner side in the vehicle width direction and that is radially outward of the inner cylindrical portion 61 and the outer cylindrical portion 51. In the arrangement space, a detection subject portion 84 of the target member 80 is provided at a position facing the sensor board 100 in the axial direction. The sensor board 100 is provided between the flange portion 62 and the hub mounting portion 52.

[0036] As shown in FIG. 4, the sensor substrate 100 has an arc shape that follows the detection target portion 84 when viewed from the front of the plate surface. As shown in FIG. 7, the sensor substrate 100 includes an excitation coil 110 and a receiving coil. In this embodiment, the receiving coils are a first receiving coil 111 and a second receiving coil 112. Each of the coils 110 to 112 is a planar coil that follows the plate surface of the arc-shaped substrate. The substrate is a multi-layer substrate. Each of the coils 110 to 112 is formed by wiring patterns, vias, etc., formed on each layer of the substrate.

[0037] The sensor substrate 100 includes an excitation circuit 113 that supplies a high-frequency excitation voltage to the excitation coil 110, and a receiving circuit 114. The excitation circuit 113 and the receiving circuit 114 are provided on the substrate. When an excitation voltage is supplied to the excitation coil 110, an excitation current flows through the excitation coil 110, and a voltage having the same or equivalent frequency as the excitation voltage is induced in each of the coils 111 and 112. The receiving circuit 114 detects output voltage signals at both ends of each of the coils 111 and 112. When an excitation voltage is supplied to the excitation coil 110, the phase difference between the first output voltage signal of the first receiving coil 111 and the output voltage signal of the second receiving coil 112 is 90 degrees.

[0038] In this embodiment, the coils 110 to 112 have the same circumferential center position. The circumferential center position of each of the coils 110 to 112 is located opposite the lower end of the detection object portion 84 in the axial direction.

[0039] The sensor board 100 is provided with a connector 115 that is electrically connected to the excitation circuit 113 and the receiving circuit 114. The connector 115 is electrically connected to a processing unit 117 via a cable 116. The processing unit 117 may be provided on the vehicle body or may be built into the wheel unit 10.

[0040] The processing unit 117 includes a CPU (Central Processing Unit). The functions of the processing unit 117 can be provided by software stored in a physical memory device and a computer executing the software, by software alone, by hardware alone, or by a combination of these. For example, if the microcomputer of the processing unit 117 is provided by a hardware electronic circuit, the function can be provided by a digital circuit including multiple logic circuits or an analog circuit. For example, the microcomputer executes a program stored in a non-transitory tangible storage medium serving as a storage unit of the microcomputer. The program includes, for example, a program for a load calculation process, which will be described later. A set of instructions constituting the program is executed to perform a method corresponding to the program. The storage unit is, for example, a non-volatile memory. The program stored in the storage unit can be updated via a communication network such as the Internet, for example, via OTA (Over The Air) or the like.

[0041] Next, the load calculation process will be described.

[0042] 2, when a lateral force Fy acts on the wheel, the inclination θ of the central axis LCi of the inner ring member 60 relative to the central axis of the outer ring member 50 increases. In this case, the axial distance between each of the coils 111, 112 and the detection object 84 changes, and the amplitude of the output voltage signal of each of the coils 111, 112 changes. Based on this change in amplitude, the processing unit 119 calculates the axial displacement ΔY of the detection object 84, and performs processing to calculate the lateral force Fy based on the calculated axial displacement ΔY.

[0043] On the other hand, when a vertical load Fz acts on the wheel, the central axis LCi of the inner ring member 60 is displaced in a direction perpendicular to the central axis of the outer ring member 50. As a result, the target member 80 fixed to the flange portion 62 is also displaced. In this case, the sensor board 100 is configured so that the amplitude of the output voltage signals of the first receiving coil 111 and the second receiving coil 112 changes. Based on this change in amplitude, the processing unit 117 calculates the displacement of the detection object portion 84 in a direction perpendicular to the axial direction and the vehicle length direction (hereinafter referred to as the vertical displacement ΔZ), and performs processing to calculate the vertical load Fz based on the calculated vertical displacement ΔZ.

[0044] The processing unit 117 calculates the rotation angle of the wheel based on the output signal of at least one of the first receiving coil 111 and the second receiving coil 112. The processing unit 117 calculates the rotation speed of the wheel based on the calculated rotation angle. Specifically, for example, the processing unit 117 may calculate the rotation speed based on the time differential value of the rotation angle.

[0045] The coils 110 to 112 and the load calculation process are described in, for example, Japanese Patent Application Laid-Open No. 2023-130285.

[0046] Next, a configuration for fixing the relative position of the sensor board 100 with respect to the outer ring member 50 of the hub bearing 40 will be described with reference to FIGS.

[0047] The wheel unit 10 includes a bracket member 120. The bracket member 120 is made of a non-magnetic material, for example, synthetic resin or a metal material (e.g., aluminum). The bracket member 120 includes a bracket base 121 that serves as a base for the bracket member 120. The bracket base 121 is plate-shaped and has an annular shape. A circular (specifically, perfect circular) through-hole 122 is formed in the center of the bracket base 121. The through-hole 122 passes through in the axial direction from the first plate surface 121a to the second plate surface 121b of the bracket base 121, and the outer cylindrical portion 51 is fitted into the through-hole 122.

[0048] The bracket member 120 includes a thick portion 123 and a protrusion 124 as components for attaching the sensor board 100. The thick portion 123 extends from the first plate surface 121a of the bracket base 121 toward the flange portion 62 in the axial direction. The thick portion 123 has an arc shape that extends in the circumferential direction.

[0049] The protrusion 124 extends axially from the first plate surface 121a of the bracket base 121 toward the flange 62. The protrusion 124 is formed with bolt insertion holes 126 that penetrate in the axial direction and through which the board mounting bolts 125 are inserted. Bolt insertion holes 127 that penetrate in the axial direction and through which the board mounting bolts 125 are inserted are formed in each circumferentially spaced portion of the thick-walled portion 123. Meanwhile, the sensor board 100 is formed with the same number of female threaded holes 101 as the bolt insertion holes 126, 127, into which the male threads of the board mounting bolts 125 are screwed.

[0050] In the bracket base 121, at a position shifted in the circumferential direction from the protrusion 124 and the thick portion 123, a bolt insertion hole 128 is formed, which penetrates from the first plate surface 121a to the second plate surface 121b and through which the bolt 16 is inserted. In this embodiment, three bolt insertion holes 128 are formed spaced apart in the circumferential direction.

[0051] The dust cover 70 includes a first wall portion 73, a connecting portion 74, and a second wall portion 75. The connecting portion 74 extends radially outward from the radially outer end portion of the first wall portion 73. The second wall portion 75 extends radially outward from the radially outer end portion of the connecting portion 74.

[0052] The first wall portion 73 of the dust cover 70 has a circular (specifically, perfect circular) through-hole 72 formed therein, which extends in a direction perpendicular to the plate surface of the first wall portion 73 and into which the outer cylindrical portion 51 is fitted. The knuckle 15 has a circular (specifically, perfect circular) through-hole 15a formed therein, which extends in the axial direction and into which the outer cylindrical portion 51 of the outer ring member 50 is fitted.

[0053] A bolt insertion hole 71 through which the bolt 16 is inserted is formed in the first wall portion 73 of the dust cover 70. A bolt insertion hole 15b through which the bolt 16 is inserted is formed in the knuckle 15.

[0054] The outer cylindrical portion 51 of the hub bearing 40 is provided with hub mounting portions 52 extending in the radial direction. The number of hub mounting portions 52 provided is the same as the number of bolt insertion holes 128. The hub mounting portions 52 are spaced apart in the circumferential direction. As shown in FIGS. 3 and 4, the hub mounting portions 52 are formed with female threaded holes 52a that pass through in the axial direction and into which the bolts 16 are screwed. The hub mounting portions 52 are formed with flat surfaces 52b that extend in a direction perpendicular to the axial direction.

[0055] The first plate surface 121a of the bracket member 120 is brought into contact (specifically, surface contact) with the flat surface 52b of the hub mounting portion 52, and the dust cover 70 and the knuckle 15 are placed on top of the bracket member 120. In this state, the bolt 16 is inserted into the bolt insertion holes 71, 128, and the male thread of the bolt 16 is screwed into the female threaded hole 52a of the hub mounting portion 52. This fixes the bracket member 120, outer ring member 50, and dust cover 70 so that they cannot be displaced relative to the knuckle 15. The bracket member 120 and the dust cover 70 are formed with cable insertion holes 129, 78 through which the cable 116 connected to the connector 115 of the sensor board 100 is inserted (see FIGS. 4, 8, 9, etc.).

[0056] After the bracket member 120 is attached to the hub bearing 40, the female screw hole 101 of the sensor board 100 is aligned with the bolt insertion hole 126 of the protrusion 124 and the bolt insertion hole 127 of the thick-walled portion 123. In this aligned state, the board mounting bolt 125 is inserted into the bolt insertion holes 126 and 127 from the first plate surface 121a side of the bracket base 121, and the male thread of the board mounting bolt 125 is screwed into the female screw hole 101. As a result, both circumferential ends and a circumferential middle portion of the sensor board 100 are fixed to the bracket member 120 with the sensor board 100 and the bracket member 120 maintaining a predetermined relative positional relationship. More specifically, the sensor board 100 is fixed to the bracket member 120 with the first plate surface 102a facing the detection target portion 84 and the second plate surface 102b abutting against the thick-walled portion 123. In this case, the first plate surface 102a and the second plate surface 102b of the sensor board 100 are parallel to the plate surface of the bracket base 121. The second plate surface 102b is the back surface of the first plate surface 101a. The sensor board 100 is supported by the protrusions 124 and the thick portions 123 in a state spaced apart from the first plate surface 121a of the bracket base 121.

[0057] The bracket member 120 can determine the relative positions of the sensor board 100 and the detection target portion 84. For example, by adjusting the axial length dimensions of the thick portion 123 and the protrusion 124 of the bracket member 120 at the time of design, it is possible to adjust the gap between the flat surface 82a of the protrusion 82 and the first plate surface 102a of the sensor board 100. As a result, it is possible to reduce the effect of the shape of the hub bearing 40 on the mounting mode of the sensor board 100 for aligning the first plate surface 102a with the detection target portion 84. This makes it possible to minimize changes to the shape of the sensor board 100, even if the shape of the hub bearing changes depending on the type of vehicle, for example.

[0058] Incidentally, the temperature of each of the coils 110-112 rises as a result of current flowing through the coils 110-112. The temperature of each of the coils 110-112 also rises due to heat generated when the brake pad is pressed against the disc sliding portion 23. The temperature rise of each of the coils 110-112 affects the voltage signals output from the receiving coils 111, 112, which may reduce the accuracy of detecting displacement or force.

[0059] Therefore, in this embodiment, as a configuration for suppressing the temperature rise of each of the coils 110-112, ventilation holes 130 are formed in the thick-walled portion 123 of the bracket member 120, as shown in Figs. 8 to 11, etc. The ventilation holes 130 are holes that penetrate the thick-walled portion 123 in the radial direction. A plurality of ventilation holes 130 are formed and aligned in the circumferential direction. In particular, in this embodiment, as shown in Fig. 11, each ventilation hole 130 extends in the axial direction to the base end of the thick-walled portion 123 on the bracket base portion 121 side. This increases the area of ​​the ventilation holes 130. Note that Fig. 11 is a cross-sectional view of the bracket member 120.

[0060] The multiple ventilation holes 130 can improve the heat dissipation properties of the thick portion 123. This can suppress a temperature rise in the sensor substrate 100 whose second plate surface 102b is in contact with the thick portion 123. As a result, a temperature rise in the exciting coil 110 and the receiving coils 111, 112 can be suppressed.

[0061] 3, the sensor substrate 100 is disposed radially inward of the air intake 31 of the disc rotor 21. In this case, as the disc rotor 21 rotates, an air flow is generated in each air passage 30a, and also in each ventilation hole 130. As a result, the thick portion 123 can be effectively cooled, and the temperature rise of the sensor substrate 100 can be effectively suppressed.

[0062] The sensor board 100 is spaced apart from the bracket base 121. This allows an air passage to be formed between the sensor board 100 and the bracket base 121. This improves the heat dissipation of the sensor board 100, and prevents the temperature of the sensor board 100 from rising.

[0063] Second Embodiment The second embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment. The bracket member of this embodiment has a structure in which a groove is formed in the thick portion. This structure will be described below with reference to Figures 12 to 14.

[0064] Similar to the bracket member 120 of the first embodiment, the bracket member 220 includes a bracket base 221 and a protrusion 224. The bracket base 221 includes a first plate surface 221a and a second plate surface 221b. In the bracket member 220, the through hole 222, the bolt insertion holes 226, 227, 228, and the cable insertion hole 229 correspond to the through hole 122, the bolt insertion holes 126, 127, 128, and the cable insertion hole 129 of the first embodiment.

[0065] The bracket member 220 includes a thick portion 223. The thick portion 223 has an arc shape extending in the circumferential direction. A groove portion 230 extending in the circumferential direction is formed in the side surface of the thick portion 223. A plurality of groove portions 230 are formed and aligned in the axial direction. In particular, in this embodiment, each groove portion 230 is formed over the entire circumferential area of ​​the side surface of the thick portion 223.

[0066] As the disc rotor 21 rotates, an airflow is generated in each air passage 30a. This also generates an airflow in each groove 230. As a result, the thick portion 123 can be cooled, and the temperature rise of the sensor substrate 100 can be suppressed.

[0067] <Other embodiments> The above-described embodiments may be modified as follows.

[0068] In the second embodiment, a groove may be formed on the side surface of the thick portion 223, extending in the axial direction instead of the circumferential direction.

[0069] In the first embodiment, as long as the sensor board 100 abuts against the thick portion 123, the portion of the bracket member 120 where the sensor board 100 is fixed is not limited to the thick portion 123. The same applies to the second embodiment.

[0070] In the target member 80, a hole that passes through the target member 80 in the axial direction may be formed instead of the recess 83. The hole is a portion that is recessed toward the flange portion 62 side relative to the protrusion 82.

[0071] The hub bearing is not limited to an inner ring rotation type, and may be an outer ring rotation type. Specifically, the inner ring axial member (corresponding to the "first bearing member") constituting the outer ring rotation type hub bearing has an inner cylindrical portion (corresponding to the "first cylindrical portion") extending axially and is fixed to the knuckle 15. The outer ring axial member (corresponding to the "second bearing member") constituting the hub bearing has an outer cylindrical portion (corresponding to the "second cylindrical portion") provided radially outside the inner cylindrical portion, and a flange portion extending radially from the outer cylindrical portion and to which the wheel is fixed.

[0072] The circumferential center positions of the first and second receiving coils 111, 112 may be located at a position axially facing the right or left end of the target member 80, rather than at a position axially facing the lower or upper end of the target member 80. In this case, the sensor board 100 and the processing unit 119 can calculate the force acting between the ground contact surface GL and the wheel in the vehicle length direction (hereinafter referred to as the longitudinal load Fx) instead of the vertical load Fz. The direction in which the lateral force Fy acts is perpendicular to the direction in which the longitudinal load Fx acts. The longitudinal load Fx is used by the control device to control the running of the vehicle.

[0073] The disc rotor is not limited to a ventilated disc, but may be, for example, a solid disc made of a single circular plate. [Explanation of symbols]

[0074] 10...wheel unit, 15...knuckle, 40...hub bearing, 80...target member, 100...sensor board, 110...excitation coil, 111, 112...receiving coils, 120...bracket member, 121...bracket base, 123...thick portion, 130...ventilation hole.

Claims

1. Wheels (11, 14) of a vehicle; a hub bearing (40) that rotatably supports the wheel relative to a knuckle (15) of the vehicle; a disc rotor (21) constituting a brake device (20); A detection device applied to a wheel unit (10) comprising: The hub bearing is a first bearing member (50) having a first cylindrical portion (51) extending in an axial direction, which is the direction of the rotational center axis of the hub bearing, and fixed to the knuckle; a second bearing member (60) having a second cylindrical portion (61) provided at a position facing the first cylindrical portion in a radial direction perpendicular to the axial direction, and a flange portion (62) extending radially outward from the second cylindrical portion and to which the disk rotor is fixed; a rolling element (41) provided between the first cylindrical portion and the second cylindrical portion; the second bearing member is rotatably supported relative to the knuckle, The disk rotor has a disk sliding portion (23) that is disposed radially outward relative to the hub bearing and has an annular shape, a detection target portion (84) that is provided on the knuckle side of the flange portion in the axial direction and has an annular shape extending in the circumferential direction of the second cylindrical portion; A sensor substrate (100); Equipped with The detection target portion is provided with convex portions (82) that protrude toward the knuckle in the axial direction and portions (83) that recede toward the opposite side of the knuckle from the convex portions in the axial direction, alternately in the circumferential direction, the sensor substrate outputs a voltage signal corresponding to a relative displacement of the detection target portion with respect to the sensor substrate; a bracket member (120) disposed between the knuckle and the detection target portion in the axial direction; The bracket member is a bracket base (121) disposed radially outward relative to an outer cylindrical portion (51), which is a cylindrical portion located radially outward of the first cylindrical portion and the second cylindrical portion, and extending along the circumferential direction; a thick portion (123) extending from the bracket base toward the flange portion in the axial direction; and The sensor board is fixed to the bracket member with a plate surface (102a) of the sensor board facing the detection target and in contact with the thick portion, A detection device, wherein a plurality of ventilation holes (130) that are holes penetrating in the radial direction are formed in the thick portion and aligned in the circumferential direction.

2. the disk sliding portion is disposed radially outward of the thick portion, 2. The detection device according to claim 1, wherein an air passage (30a) is formed in the disc sliding portion, the air passage (30a) extending from an air intake (31) formed on the radially inner side to an air exhaust port (32) formed on the radially outer side.

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